1. Field of the Invention
The present invention relates to a CMOS thin film transistor and a method of manufacturing the same. More particularly, the present invention relates to a CMOS thin film transistor and a method of manufacturing the same using a metal induced lateral crystallization (MILC) technique.
2. Description of the Related Art
A poly-silicon layer has been generally formed such that an amorphous silicon layer is deposited on a substrate and is crystallized at a predetermined temperature. A technique to crystallize the amorphous silicon layer includes a solid phase crystallization (SPC), an excimer laser annealing (ELA), and a metal induced lateral crystallization (MILC).
Of the techniques, the MILC has advantages in that a process temperature is low and a processing time is short compared to the other techniques. U.S. Pat. No. 5,773,327 discloses a method of manufacturing a thin film transistor (TFT) by crystallizing the amorphous silicon layer using the MILC technique. The U.S. Pat. No. 5,773,327 has disadvantages in that an additional mask is required to define an MILC region, and an MILC surface acting as defects exists in a channel region. The MILC surface is a portion in which two surfaces of crystallized polysilicon grown in opposite directions by the MILC technique meet.
Meanwhile, a multiple gate is employed to prevent a leakage current. In this case, a dimension of the TFT region is increased, and a distance between metal layers to perform the MILC process is also increased, thereby increasing a crystallization time.